Feed tripping mechanism for drilling machines



Oct. 10, 1933. w. M. FAIRBAIRN ET AL FEED TRIPPING MECHANISM FOR DRILLING MACHINES Filed Dec. 4, 1950 2 Sheets-Sheet l $2106 073 uYcLbterJ l. Fzirbwi-rrz,

Oct. 10, 1933. w. M. FAIRBAIRN ET AL FEED TRIPPING MECHANISM FOR DRILLING MACHINES Filed Dec. 4, 1930 2 Sheets-Sheet 2 i atented Unit. 10, 19 33 rric FEED TRIEPING MECHANISM FOR DRELLENG REACHINES Application December 4, 1330. Serial No. 499,879

Claims.

anism in which no latch need be employed for 15 the controlling lever, so that the lever may be moved without any delay or any unnecessary effort.

Still another object is to provide a mechanism of this character which, when the drill spindle 2O feed has been tripped at a predetermined point, may be reset to permit a continued feed to a second predetermined point without retracting the drill spindle.

Another object is to provide a mechanism of this character which has a graduated disk mounted conveniently adjacent the front of the machine and arranged to be adjustably locked in a position whereby the feeding mechanism will be automatically tripped at a predetermined point in the feeding movement of the drill spindle, as indicated by the disk.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, in which:

Figure 1 is a fragmentary elevation of the righthand side of a drilling machine having a feed tripping mechanism embodying the features of the invention.

Fig. 2 is a plan section taken approximately along the line 2-2 of Fig. l. i

Fig. 3 is a fragmentary front elevation of the machine partially in section.

Fig. 4 is a fragmentary elevation of the left hand side of the machine.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that We do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

(Cl. "HF-33) The present embodiment of the invention comprises generally a frame, a reciprocatory tool spindle, and power means for feeding said tool spindle including a rotary element and a disengageable driving connection therefor. The 60. driving connection is controlled in accordance with our invention by a tripping mechanism comprising a latch for holding the driving connection in engagement with automatically operable means for releasing the latch at a predetermined point in the travel of the spindle, and manually operable means for releasing the latch at any point in the travel of the spindle.

In the drawings, the invention is embodied in a verticahspindle type of drilling machine, but it will be obvious that it could be embodied in other types of such machines. As illustrated, the ma" chine comprises a frame in which is mounted a reciprocatory tool spindle ll rotatably driven by means not shown as it forms no part of the present invention. The spindle 11 is adapted to be reciprocated vertically to feed the tool into the work by means comprising in the present instance a non-rotatable sleeve 12 slidably supported in the frame and permitting the spindle 11 to rotate within it.

The power means provided for reciprocating the sleeve includes arotary element and a disengageable driving connection therefor adapted when engaged to drive the feed and to be disengaged to stop the feed. As illustrated, this means comprises a rack 13 (Fig. 2) cut in the side of the sleeve 12 and a rotary element or cross shaft or spindle l4. journaled in the frame and carrying a pinion 15 meshing with the rack 13. On the left-hand end of the shaft 1% as viewed from the front of the machine, a driven gear 16 is secured.

To the rear of the shaft 14, a rock shaft 20, tubular in form, is j ournaled in the frame. W ithin the rock shaft 20, a stub shaft 21 is journaled by means such as ball bearings 22 concentric with the axis of the rock shaft. On the right-hand end of the stub shaft 21 as viewed from the front of the machine, a gear 23 (Fig. 1) is secured which meshes with a gear 24, the two gears 23 and 24 comprising a pair of pick-off gears driven from the main drive shaft of the machine through change speed gearing (not shown).

0n the left-hand end of the rock shaft 20, an 105 arm 25 is formed (Fig. 4) which carries gearing driven by the stub shaft 21 and movable into and out of driving engagement with the gear 16 on the cross shaft 14. This gearing comprises a pinion 26 mounted concentrically with the rock 110 shaft 20 and secured on the right-hand end of the stub shaft 21. Meshing with the pinion 26 is a second pinion 2'? which is rotatably mounted on the free end of the ar 1 preferably by a pin 28 threaded into the ar .i. The pinion 27 is adapted to be moved into and out mesh with the gear 16 on the cross shaft 14 by swingin movement of the arm 25. Thus, a di, ngageable driving connection or clutch is for ed for feeding the tool spindle, the pinion 27 being constantly driven through the pinion 26, the shaft 21 and the pickoff gears 23 and 24, while the cross shaft 14 is driven only when the reel: shaft 20 is rotated to a position where the arm 25 holds the pinion 2'7 in mesh with the gea 16 on the cross shaft 14.

Our improved tripping mechanism has a disengageable latch for holding the driving connec tion in engagement. As illustrated herein the latch locks the rock shaft 23 against rotation when the arm 25 is swung to the position in which the pinion 2? meshes with the gear 16, thus maintaining a driving relation thercbetween. To this end, a second 3O secured to the righ hand end of the rock shaft 26 as by a pin 31. On the free end of the arm 30, a latch dog 32 is pivotally supported and is adapted to turn on a vertical axis so as to engage a fixed abutment such as a latch block 33 secured to the frame 10. To pivotally support the latch dog 32, the free end of the arm has the form of a yoke between the ends of which the latch dog 32 is mounted by means of a pivot pin The latter is secured against rotation. relative to the latch dog 32 as by a screw 35 and is rotatably mounted in the ends of the yoke. To urge the latch dog into engagement with the latch block: 33, a torsion spring 36 surrounds the upper end of the pivot pin 34 and has one end secured in the head of the pin 34 and the other in the end of the yoke, thus tending to rotate the pivot pin and turn the latch dog 32.

The latch block 33 has a ledge 37 and the latch dog 32 has a projection 33 which engage each other under the action of the torsion spring 36 whenever the arm 36 is swung upwardly to the position shown in Fig. i, and the pinion 27 is swung into mesh with the gear 16. Thus, the latch maintains a driving relation between the pinion 2'7 and gear 16.

As mentioned above, the invention includes adjustable means operable in the rotation of the rotary element or cross shaft 14 to release the latch and thus interrupt the feed at a predetermined point in the downward travel of the spindle. To this end, the cross shaft 14 (see Fig. 3) has a portion 40 of reduced diameter on its righthand end forming shoulder with the main portion of the shaft against which is mounted a disk 41 for rotation therewith. Fitting closely around the disk 41 is a 42 which is rotatively adjustable relative to the dis]: but is prevented from moving axially relative thereto as by a flange 43 formed on one side of the disk and a plate 44 mounted on the other.

The ring 42 is adapted to be locked to the disk and to rotate therewith, and carries cam means adapted to release the latch. In the present instance, this carn means comprises a beveled-face cam lug 45 formed on the side of the ring 4.2, which is adapted to strike a beveled lug 46 on the latch dog 32 in the rotation of the ring and thus pivot the latch dog 32 against the action of its spring 36. The projection 38 on the latch dog is thus disengaged from the ledge 3'? on the latch block 33 and the arm 30n1ay then turn together with the rock shaft 20 to disengage the driving connection.

To lock the ring 42 to the disk 41 so that the two will rotate together, and to permit adjustment of the ring relative to the disk so that the feed of the spindle will be stopped at a predetermined point in its travel, a pin 50 is mounted within the disk 41 for radial sliding movement relative thereto. When the 50 is pressed outwardly, it bears against the inner surface of the ring 42 and looks it against rotation relative to the disk 41. The pin 50 extends inwardly through the reduced portion 40 of the cross shaft 14 to an axial bore 51 formed therein. Within the axial bore 51, a rod 52 is mounted which has a conical inner end 53 acting as a cam surface to press the pin 50 outwardly when the rod 52 is moved to the left as shown in Fig. 3.

Adjacent the outer end of the rod 52, the latter is threaded into a portion of the bore 51 and. a knurled knob 58 is secured on the end of the rod beyond the end of the portion 40 of the cross shaft 14. Between the ends of the rod, the charm eter thereof is reduced and a pin 54 is inserted through the wall of the portion co to prevent the rod from being completely withdrawn from the portion 40.

For setting the ring 42 to drill to a predetermined depth in a piece of work, a graduated scale is provided on the periphery of the ring 42, which is calibrated to correspond with the amount of feeding movement of the spindl Cooperating with the scale on the ring 42 is a stationary mark such as a pointer 47 secured to the frame 10 adjacent, the front of the ring 42 where it may be easily seen.

On the outer end of the portion 40, a hand wheel 55 may be secured, as by a nut 56 and spacing sleeve 57, to permit the cross shaft 14 to be rotated by hand.

The invention also includes manually-operated means for releasing the latch so that the spindle feed may be stopped at any point. This means also serve to engage the driving connection between the pinion 27 and gear 16. As illustrated herein, this means comprises a hand lever 66 (see Fig. 1) pivotally supported on the so, on the right-hand side of the machine, as by a screw 61. To release the latch, a beveled surface 62 is cut on the lever which coacts with a beveled nose 63 formed on a portion 64 of the latch dog 32 which extends within the yoke of the arm 33. When the lever 60 is moved to the right as shown in Fig. l, the beveled surface 62 forces the nose 63 out of the way and pivots the latch dog 32 until its pro jection 38 is disengaged from the ledge 37 on the latch block 33. When the latch is thus released, the rock shaft 20 is free to turn and the pinion 27 may swing out of engagement with the gear 16.

When the pinion 27 is out of mesh with the gear 16 and it is desired to swing the former back into mesh to start the feeding movement of the spindle, the lever 60 is swung to the left, as shown in Fig. 1, until it strikes an abutment 66 formed on the arm 30. Continued movement of the lever by having its ends respectively positioned in pockets formed in the side of the lever 60 and in a lug 68 formed on the arm 39. Thus, the lever 60 is urged to a position in which it is out of contact with the beveled nose 63 of the latch dog.

in the operation of the mechanism, assume that a piece of work is in position under the drill spindle, and that it is desired to drill a hole to a predetermined depth, for example, four inches. -With the pinion 27 out of mesh with the 16 on the cross shaft 14, the hand wheel 55 is turned until the drill comes in contact with the work piece. The ring 42 then must be adjusted so that its cam lug 45 will release the latch and disengage the driving connection when the drill has been fed four inches.

. To effect such adjustment, the ring 42 is unlocked from the disk 41 by screwing the rod 52 outwardly so that the pin 50 will release the ring 42. The latter is then turned, without turning the cross shaft 14, until the numeral 4 on the graduated scale is alined with the stationary mark or pointer l7. The ring 42 is then looked to the disk ll for rotation with the cross shaft 14 by so v-11g the rod 52 inwardly until it forces the surface of the ring 42.

The power feed is now ready to be started, which act is accomplished by moving the hand lever 09 to the left as shown in Fig. 1. This movement brings the lever 60 in contact with the abutment 66 on the arm 30, and the latter is thus swung, as are also the rock shaft 20 and the arm until the pinion 27 is in mesh with the gear 16 on the cross shaft. Thus, the cross shaft will be driven to feed the drill spindle. In this position of the arm 30, the latch dog 32 is free to turn under the influence of the torsion spring 36 so that the projection 38 on the latch dog will engage the ledge 37 on the latch block, and the driving connection for the feed is latched in its engaged position.

As the cross shaft rotates to feed the drill spindie, the ring 42 also rotates in unison therewith until its cam lug 45 strikes the beveled lug 46 on the latch dog 32 and the latter is released, so that the arm 30, the rock shaft 20 and the arm 25 are permitted to swing, and the pinion 27 moves out of mesh with the gear 16 to stop the feed.

If it is desired to continue drilling the same hole to a greater depth than was first set onthe ring 412, the latter may be reset for the additional depth without retracting the drill from the work piece. The feed may then be restarted by moving the hand lever $0 and the feed will continue until stopped manually or through the action of the cam lug 450p the ring 42.

It is often desired to stop the feed by hand before the automatic stop, as determined by the setting of the ring 42, has reached the point at which it will operate. Also, in some drilling work, it is impractical to use the automatic stop and it is desirable to stop the feed at any point as determined by the person operating the machine.

For these purposes, the hand lever 60, as mentioned above, is arranged to release the latch, when moved to the right as shown in Fig. l, by camming the beveled nose 63 on the latch dog 32 out of the way and thus release the latch dog from the latch block.

When the hand lever. is not being used, the spring 67 forces it to a neutral position in which it is out of contact with the beveled nose 63 on the latch dog 32. Thus, the latch dog will not be released except when the lever 60 is operated by hand against the action of the spring 67.

From the above description it will be evident that we have provided a feed tripping mechanism wliicl may be set to operate automatically at any predetermined point in the feed and which may be operated manually at any time regardless of the setting for the automatic tripping. The mechanism is extremely sensitive as the latch dog 32, while it holds the driving connection in positive engagement, may be released by a relatively small pressure. The mechanism is also conveniently arranged, as all the parts which have to be reached by hand are immediately adjacent the front part of the machine and the hand lever 60 is so constructed that it is freely movable for performing its various functions.

We claim as our invention:

1. A drilling machine comprising, in combina tion, a frame, a reciprocatory tool spindle mount-- ed in the frame, a cross shaf for reciprocating said tool spindle, a gear mounted on said cross shaft, a rock shaft mounted in said frame, a pinion eccentrically mounted on said rock shaft and arranged to swing into and out of engage ment with said gear, means for driving said pinion concentric with said rock shaft, an arm carried by said rock shaft, a latch pivoted on said arm on an axis transverse to said rock shaft for engagement with said frame adapted when engaged to hold said pinion in engagement with said gear, a hand lever movable relative to said latch for disengaging said latch when moved in one direction and for moving said arm to a position where said latch may engage said frame when moved in th opposite direction, and cam means mounted on said cross shaft and arranged to engage said latch for throwing said latch out of engagement with said frame to permit said pinion to move out of engagement with said gear.

2. A drilling machine comprising, in combination, a frame, a reciprocatory tool spindle, power means for feeding said tool spindle including a rotary element and a disengageable driving connection therefor, a rock shaft controlling said driving connection, an arm mounted on said rock shaft, a latch-dog pivotally mounted on the free end of said arm, a latch plate mounted'on said frame and adapted to be engaged by said latch dog when the driving connection is engaged, a spring urging said latch dog toward said latch plate, means operable in the rotation of said element to release said latch dog, a lever pivotally mounted on said arm and adapted when moved in one direction to abut against said arm and move said rock shaft to a position where said driving connection is engaged, said lever having a cam surface formed thereon adapted when moved in the other direction to cam said latch dog out of engagement with said latch plate, and a spring interposed between said arm and said lever adapted to urge said lever to a neutral position.

3. A drilling machine comprising, in combination, a frame, a reciprocatory tool spindle, power means for feeding said tool spindle including a rotary element and a disengageable driving connection therefor, manually operable means for rotating said element, means for holding said driving connection in engagement including a movable member, a spring-operated latch dog movably mounted on said movable member, and a latch member mounted on said frame and adapted to be automatically engaged by said latch dog when said movable member is moved to the position where the driving connection is in engagement, a cam mounted for rotation with said rotary element and operable to move said dog out of engagement with said latch member to permit said movable member to disengage said driving connection and carry said dog out of the path of said cam whereby said element may be rotated manually, and a hand lever movable in one direction for disengaging said latch dog and movable in the opposite direction for engaging said driving connection.

4. A drilling machine comprising, in combination, a frame, a vertically reciprocatory tool spindle mounted in the frame, means for reciprocating said tool spindle, driving means, a disengageaole connection between said reciprocating and driving means, a horizontal rock shaft carrying said connection and adapted when swung by gravity to disengage said connection, an arm secured on said rock shaft against rotation relative thereto and normally extending horizontally therefrom, a spring actuated latch dog pivoted on a substantially vertical axis on said arm and adapted to engage said frame to prevent swinging of said rook shaft, and means for disengaging said latch dog from said frame to permit said roclr shaft to swing and disengage said driving connection.

5. A drilling machine comprising, in combination, a frame, a reciprocatory tool spindle, power means for feeding said tool spindle including a rotary element and a disengageable driving connection therefor, a rock shaft controlling said driving connection, an arm mounted on said rock shaft, a latch dog pivotally mounted on an axis transverse to the axis of the rock shaft on the free end of said arm and adapted to engage said frame when the driving connection is engaged, a spring urging said latch dog toward its engaging position, and a lever pivotally mounted on said arm independently of said latch dog and adapted when moved in one direction to abut against said arm and move'said rock shaft to a position where said driving connection is engaged and when moved in the opposite direction to swing said latch dog out of engagement with said frame.

WALTER M. FAIRBAIRN. FRED M. HANNA. 

